Dependence on tobacco derived nicotine is a major public health problem. Substance users who complete training in mindfulness subjectively report increased patience and improved motor control over their impulses. Yet, no studies have tested this perceived benefit with behavioral measures of impulse control. The investigators are conducting a randomized controlled clinical trial, which compares Cognitive-Behavioral Therapy and Mindfulness Training for tobacco smokers, using behavioral measures to investigate the effects of mindfulness training on impulsivity and inhibitory control.